Fix E2E test gaps and add comprehensive E2E + parity test suites

- Fix pull consumer fetch: send original stream subject in HMSG (not inbox)
  so NATS client distinguishes data messages from control messages
- Fix MaxAge expiry: add background timer in StreamManager for periodic pruning
- Fix JetStream wire format: Go-compatible anonymous objects with string enums,
  proper offset-based pagination for stream/consumer list APIs
- Add 42 E2E black-box tests (core messaging, auth, TLS, accounts, JetStream)
- Add ~1000 parity tests across all subsystems (gaps closure)
- Update gap inventory docs to reflect implementation status

src/NATS.Server/Raft/RaftConfig.cs

@@ -0,0 +1,20 @@
+namespace NATS.Server.Raft;
+
+/// <summary>
+/// RAFT runtime configuration model aligned with Go's raftConfig shape.
+/// Go reference: server/raft.go raftConfig (Name, Store, Log, Track, Observer,
+/// Recovering, ScaleUp).
+/// </summary>
+public sealed class RaftConfig
+{
+    public string Name { get; set; } = string.Empty;
+
+    // Store/log abstractions are intentionally loose until full WAL/store parity is wired.
+    public object? Store { get; set; }
+    public object? Log { get; set; }
+
+    public bool Track { get; set; }
+    public bool Observer { get; set; }
+    public bool Recovering { get; set; }
+    public bool ScaleUp { get; set; }
+}